Apparatus for fitting shoe uppers

ABSTRACT

In order to reduce the possibility of producing cracks and other damages when lasting shoe uppers, the fore and back parts of the last are used as a mold core for shaping the upper, in combination with die means having concavities conforming to the desired shoe pattern. The last is of the type comprising two sections hingedly interconnected substantially intermediate its ends and near its bottom. The disclosed apparatus comprises a central portion for mounting the upper upside down, a front unit for shaping and tuning the front part of the upper, and a back unit for shaping the heel part of the upper.

United States Patent 1191 Holt et al. Mar. 26, 1974 [5 APPARATUS FORFITTING SHOE UPPERS 1,388,120 8/1921 Pope 12/142 MC 2 4 l 9 [75]inventors: Terence Albert Holt; Jean-Gabriel Kambongn at al 12/145Barre, both of Lyon, France Przmary ExammerPatr1ck D. Lawson AsslgneelCentre Technique Du Robe, Attorney, Agent, or Firm-Karl F. Ross; HerbertFrance Dubno [22} Filed: Mar. 27, 1972 [21 Appl. N0.: 238,565 [57]ABSTRACT In order to reduce the possibility of producing cracks 30Foreign Application p i i D and other damages when lasting shoe uppers,the fore Apr 6 1971 Fmnce 71 13208 and back parts of the last are usedas a mold core for shaping the upper, in combination with die means hav-52} us. on. 12/85 12/145 ing concavities conforming the desired Shoe 51int. 01 A4511 21/00 The last is of the type Co'Prismg swims [58] Fieldof Search H 12/7 81 8'5 12 145 hingedly interconnected substantiallyintermediate its 5 2 ends and near its bottom. The disclosed apparatuscomprises a central portion for mounting the upper [56] References Citedupside down, a front unit for shaping and tuning the front part of theupper, and a back unit for shaping UNITED STATES PATENTS the heel partof the upper. 1110.323 9/1914 Hamilton .1 l2/l45 1 135946 4/1915Brothers 12/145 7 Claims, 8 Drawing Figures APPARATUS FOR FITTING SHOEUPPERS FIELD on THE INVENTION The present invention relates to thetechnique of fitting the fore and back parts of a shoe upper on asuitable last, with folding or turning of its projecting marginalconnecting portions over the insole.

DESCRIPTION OF THE PRIOR ART In most instances the back and front partsof an upper are assembled on two separate machines, although lastingmachines are known to perform a simultaneous assembling operation. Themethods involved are based on the application of carefully localizedtractive efforts causing the upper to withstand considerable strainconstituting a frequent cause of lasting failures and therefore ofcostly rejects. To perform this lasting operation successfuly by meansof recent technical methods, the lasting machine must be adjusted foreach new upper, a job that only very skilled operators can perform,owing notably to the great variety of shoe materials and to the risk ofimproper stress distribution.

When the shoe styles change or in case of excessive size differences, itmay become necessary to change the equipment.

At present, during the lasting of the front part of a shoe the uppercovering the last is engaged between pincers which are subsequentlyreclosed. The number of such pincers may vary from three to l l and eachpair of pincers is adapted to assume any desired direction in space, inorder to ensure an extremely accurate positioning of the upper.

In the case of a decorated and luxury upper this operation may berelatively long and delicate, for during the upper positioning the lastis moved up and down in order to determine the possible upper reactions.In fact, in this type of fitting the upper does not slide on the lastbut, as soon as a contact is established, tension stresses and a certainelongation are observed at the points of contact.

When it is deemed that the upper is properly positioned, the last isfitted definitely in the upper by either actually raising the last orsimultaneously lowering the assembling pincers.

This operation is necessary for eliminating pleats tending to develop onthe upper as a consequence of the conversion of a flat surface into avolume.

It was proved that this method was attended by increments as high as topercent in the surface area, chiefly in the front part of the last. Whenbidimensional elongations of this magnitude (which may even be increasedby the last style employed) are produced, cracks tend to develop in theupper and may cause this upper to be rejected.

Moreover, this lasting method involves the application of stressesdefinitely greater in the direction of the longitudinal axis of theupper. Therefore, the lateral forces that should be applied to the upperare not sufficient and the shape is far from having the desiredfidelity, notably in the top portion of the upper. As a result, theupper does not adhere to the concave portions of the last.

At present, the lasting of the rear part of an upper is performed onlyafter preshaping the counter on a metal die by using an inflatablebladder or a the like.

According to the specific type of counter utilized (stiffening countersoftened by using suitable solvents or by the action of heat), thepreshaping operation is designed as a rule to impart to the rear part ashape approximating the finished shape obtained after the final lastingoperation.

This preshaping operation, also intended to impart a sufficientmalleability to the stiffening counter, is accomplished either byaccelerating the rate of solvent evaporation (in order to increase thestiffness of the counter if the latter is initially too soft) or byheatsoftening the counter if it is deemed too hard.

Then the sides are fitted by using a machine adapted to fold theprojecting marginal portions of the upper over the insole to which theseportions are caused to adhere by cementing or nailing.

It may be noted that in the conventional technique only the lasting ofthe fore-part of the upper is attended by a tractive force exerted onthe upper, the lasting of the back or heel part requiring mainlycompressive forces.

It is apparent that the fitting and lasting of the fore and back partsof the upper of a shoe involves many operations, different machines,considerable handling and skilled hands.

It is the primary object of the present invention to avoid the variousinconveniences mentioned hereinabove and more particularly to improvethe quality of industrial shoes while reducing the risk of damaging theupper while also shortening the lasting time.

SUMMARY OF THE INVENTION In accordance with this invention we'utilize asa mold core the fore and back portions of the assembling last forshaping the upper, in combination with die members having concavitieswhich conform to of the pattern of the shoe to be produced.

Thus, the upper is deformed under the best possible conditions andadheres perfectly to the corresponding portions of the last.

When the upper has thus been deformed and caused thus improve theshaping of the central portion of the upper on the last and moreparticularly the top surface thereof.

An apparatus for carrying out this method, in accordance with ourinvention, comprises essentially:

a central assembly adjustable in the longitudinal direction for properlyplacing the last in its upside-down position a front assembly forlasting the fore part of the upper, which comprises a fixed butadjustable die provided with a pair of movable jaws for folding theprojecting marginal portions of the upper by means of a presser elementsuch as a cylinder-and-piston unit or jacks capable of sinking the forepart of the last into the die, and also by means of othercylinder-and-piston units or jacks for pressing the upper edges againstthe die edges until the last has been properly sunk, and

a rear assembly for lasting the back or heel part of the upper, whichcomprises a die displaceable to press same against the last and providedwith another pair of movable folding jaws.

This machine is constructionally relatively simple and capable of givingvery satisfactory results it can be easily incorporated into anautomatic industrial shoe-making line.

In a preferred embodiment the central support is connected to acylinder-and-piston unit adapted to drive this support away from the diecoacting with the fore part of the last, during the deformation of thecorresponding portion of the upper in order to impart longitudinalstresses to the upper simultaneously with the transverse stressesresulting from such deformation.

The invention will be better understood from the following descriptiongiven with reference to the accompanying drawing illustratingdiagrammatically by way of example a typical embodiment of the apparatusaccording to our invention. In the drawing BRIEF DESCRIPTION OF THEDRAWING FIGS. 1 and 2 are side-elevational views showing in section thelasting apparatus according to this invention before and during theupper deformation FIGS. 3, 4, 5 and 6 are sections taken along the line44 of FIG. 2, showing some of the various steps of the upper-deformationprocess FIG. 7 is a top plan view showing on a larger scale the assemblyprovided for shaping the back part of the upper; and

FIG. 8 is a section taken along the line 8-8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus illustrateddiagrammatically in the drawing comprises three main assemblies, i.e., acentral assembly or unit 2, a front assembly 3 for shaping the fore ortoe part of the upper, and a rear assembly 4 for shaping the heel orback part of the upper.

The central assembly 2 comprises a slide 5 movable longitudinally on atransversely movable carriage 6. This carriage is adapted to travel on atrack 7 rigid with a fixed frame structure 8. Of course, means (notshown) are provided for locking the carriage 6 against motion during theupper-shaping operation. The slide 5 carries a fixed rod 9 and a pivotrod 10 fulcrumed at 12 and connected tothe piston rod of a control unitor jacks 13 of the piston-and-cylinder type. The aforesaid rods 9 and 10are adapted to be inserted into corresponding bores formed in the backportion of a last 14.

Preferably, this last 14 is of the type described and illustrated in theFrench Pat. No. 2,131,098 mentioned hereinabove. It is locked inposition by altering the relative spacing of the pair of rods 9, 10under the control of jack 13.

Finally, the slide 5 is connected to another fluidactuatedcylinder-and-piston unit or jack 31 adapted to shift this slide 5longitudinally in relation to the assembly 3 for shaping the toe or forepart of the upper.

The front assembly 3 comprises a die 15 carried by a support 16fulcrumed at 17 to a base plate 11 vertically adjustable in relation tothe frame structure 8. This assembly 3 further comprises a plurality ofcylinder-andpiston units or jacks 18 disposed all around the die 15 andadapted to press the marginal portions of the upper against this die,another fluid-actuated unit or jack 19 adapted to engage the toe end ofthe upper, and finally a cylinder-and-piston unit or jack 20 foractuating a pair of folding plates or jaws 22.

The rear assembly 4 intended for shaping the back or heel portion of theupper comprises a die 23 fitted in a holder 24 secured to the outer endof the piston rod ofa cylinder-and-piston unit or jack 25 having itscylinder carried by a support 23 movable longitudinally in relation tothe frame structure 8 of the apparatus. The holder 24 is also rigid withthe cylinder of another jack 26 having its piston rod adapted to actuatea pair of folding plates or jaws 27.

The dies 15 and 23 are produced by casting on a pattern of the desiredarticle a self-hardening polymer of the type developing a polyadditionor polycondensation reaction process. These exothermic reactions permitof producing dies without any destruction of materials, such as leather,constituting the pattern on which the dies are molded. The exothermicreaction may be adjusted, e.g., by modifying the catalyst percentage.

Prior to any operation, the apparatus according to this invention isadjusted in conformity with the last to be used therein. The lower faceof the insole 29 fitted on the last, i.e., on the upper face of thislast as seen in FIGS. 1 and 2, is first made level with the upper faceof die 23 by adjusting nuts 28 on the screw-threaded rods 9 and 10.Then, the base plate 11 is adjusted verti cally while the support 16 isadjusted by pivoting same about its fulcrum pin 17 so that the topsurface of die 15 becomes coplanar with the face of insole 29 hearingagainst the last, then in its closed position.

It should be noted that these various adjustments are required only whenchanging from one last to another.

When the adjustment operations are completed, the insole 29' is fittedto the last 14. The fore part of the upper 30 is placed on the die 15and retained thereon by means of clamping jacks 18, as shown in FIG. 3.Slide 5 is moved by means ofjack 31 toward the assembly 3, as shown byarrow 34; then the last 4 with its insole 29 is introduced into theupper and mounted on the pair of rods 9 and 10, and locked in positionby means of jack 13. Slide 5 is moved back toward the assembly 4 by ajack 31 (arrow 35), approaching its initial position to an extentdepending of course on the shoe size of the last.

This movement of the slide is not absolutely neces sary but facilitatesthe shaping of the top portion of the upper. Upon completion of theseoperations, per" formed manually, the shaping and fitting of the shoeelements can take place in a fully automatic manner.

The jack 19 is supplied with fluid under pressure to that its piston rodwill bear against the toe part of the last 14 for pressing same into thedie 15. The fore part of the last 14 will thus engage the confrontingportion of upper 30 and thus cause the latter to conform to theconcavity of die 15. During this movement the jacks l8 restrain theslippage of the marginal portions of the upper in the direction of thearrows 32 of FIG. 4. When the fore part of the upper is shaped andconforms pen fectly to the shape of the die, the piston rods of units 18are retracted while the jaw-actuating jack 2t) is supplied with fluidunder pressure for actuating the folding plates 22. In conventionalfashion these plates 22 fold the forward parts of the marginalconnecting portions 33 of upper 30 over the insole 29 until they assumethe position illustrated in FIG. 6, in which they are maintained bycementing or otherwise.

At the same time as the fore part of the upper is shaped, or during asubsequent operation, the jack is supplied with fluid in order to movethe holder 24 in the direction of the arrow 34 of FIG. 2 and bring thedie 23 against the upper 30, engaging the confronting heel portion oflast 14. As a result, the back part of the upper is shaped between thelast 14 and die 23 as shown in FIG. 8. The jaw-actuating jack 26 is thenoperated to cause the folding plates 27 to turn the rear parts of themarginal portions 33 around the back portion of the insole 29.

Under these conditions, the fore and back parts of the shoe upper areshaped and fitted, and the central portion thereof is shaped by simplyopening the last 14 as described in the aforementioned French Pat. No.2,131,098.

Upon completion of the upper-shaping operation performed by means ofthis apparatus, the carriage 6 is moved along its track toward otherstations where complementary assembling operations are accomplished.

Although a specific embodiment has been described herein with referenceto the accompanying drawing, it will readily occur to those conversantwith the art that various modifications may be imparted thereto withoutdeparting from the spirit and scope of the invention as set forth in theappended claims.

What we claim as new is 1. An apparatus for fitting a shoe upper arounda last, comprising:

a supporting structure;

a central assembly on said structure provided with mounting means forholding a last in an inverted position;

a front assembly on said structure adjacent said central assemblyincluding movable first die means with a first concavity matinglyconfronting a fore part of the mounted last, releasable clamping meanson said first die means for engaging opposite marginal portions of aforward part of a shoe upper spanning said first concavity, and firstpressure means engageable with said fore part of the last for forcingsame into said first concavity to deform said forward part of the shoeupper, said first die means being provided with first jaw means operableto fold said marginal portions of said forward part over the sole of theinverted last upon release of said clamping means; and

a rear assembly on said structure adjacent said central assemblyincluding movable second die means with a second concavity confronting aback part of the mounted last and second pressure means for displacingsaid second die means toward said central unit to deform a rear part ofthe shoe upper between said back part of the last and said secondconcavity, said second die means being provided with second jaw meansoperable to fold opposite marginal portions of said rear part of theshoe upper over the sole of the inverted last.

2. An apparatus as defined in claim 1 wherein said central assembly isshiftable on said structure toward and away from said front assembly,further comprising drive means for so shifting said central assembly.

3. An apparatus as defined in claim 2 wherein said central assemblycomprises a carriage slidably supporting said mounting means andcarrying said drive means, said structure forming a track for saidcarriage extending transversely to the direction of shift of saidcentral assembly.

4. An apparatus as defined in claim 3 wherein said first and secondpressure means and said drive means are respective fluid-operated jacks.

5. An apparatus as defined in claim 1 wherein said clamping meanscomprises a set of fluid-operated jacks.

6. An apparatus as defined in claim 1 wherein said first and second jawmeans are provided with fluidoperated actuators.

7. An apparatus as defined in claim 4 wherein said front assemblyincludes a pivotal mounting for said first die means enabling same to beswung about a horizontal axis.

1. An apparatus for fitting a shoe upper around a last, comprising: asupporting structure; a central assembly on said structure provided withmounting means for holding a last in an inverted position; a frontassembly on said structure adjacent said central assembly includingmovable first die means with a first concavity matingly confronting afore part of the mounted last, releasable clamping means on said firstdie means for engaging opposite marginal portions of a forward part of ashoe upper spanning said first concavity, and first pressure meansengageable with said fore part of the last for forcing same into saidfirst concavity to deform said forward part of the shoe upper, saidfirst die means being provided with first jaw means operable to foldsaid marginal portions of said forward part over the sole of theinverted last upon release of said clamping means; and a rear assemblyon said structure adjacent said central assembly including movablesecond die means with a second concavity confronting a back part of themounted last and second pressure means for displacing said second diemeans toward said central unit to deform a rear part of the shoe upperbetween said back part of the last and said second concavity, saidsecond die means being provided with second jaw means operable to foldopposite marginal portions of said rear part of the shoe upper over thesole of the inverted last.
 2. An apparatus as defined in claim 1 whereinsaid central assembly is shiftable on said structure toward and awayfrom said front assembly, further comprising drive means for so shiftingsaid central assembly.
 3. An apparatus as defined in claim 2 whereinsaid central assembly comprises a carriage slidably supporting saidmounting means and carrying said drive means, said structure forming atrack for said carriage extending transversely to the direction of shiftof said central assembly.
 4. An apparatus as defined in claim 3 whereinsaid first and second pressure means and said drive means are respectivefluid-operated jacks.
 5. An apparatus as defined in claim 1 wherein saidclamping means comprises a set of fluid-operated jacks.
 6. An apparatusas defined in claim 1 wherein said first and second jaw means areprovided with fluid-operated actuators.
 7. An apparatus as defined inclaim 4 wherein said front assembly includes a pivotal mounting for saidfirst die means enabling same to be swung about a horizontal axis.